var lunbo1 = document.querySelector('.lunbo1');
var before = document.querySelector('.before');
var after = document.querySelector('.after');
var b = document.querySelector('.b');
b.addEventListener('mouseenter', function() {
    before.style.display = 'block';
    after.style.display = 'block';
});
b.addEventListener('mouseleave', function() {
    before.style.display = 'none';
    after.style.display = 'none';
});
before.addEventListener('click', function() {

});
after.addEventListener('click', function() {

});

function tt() {
    timer = setInterval(function() {
        after.click();
    }, 1000)
}